Answer to Question #171922 in General Chemistry for Erin

Question

If the molar heat of fusion of sodium is 2.63 kJ/mol, how much energy is needed to melt 180 g of solid sodium at its melting point?

Answer 1

q = n $\Delta H_{fus}$

$\Delta H_{fus}$ = + 2.63 KJ/mol heat needed for melting

q = heat released

n = the number of moles of the substance

n = mass/molar mass

n = 180/22.98 = 7.83 mol

q = 7.83mol ×2.63 KJ/mol

q = 20.59 KJ